Calculated Column or Measure?

[one3nine0]

This is all in PowerPivot 2010.

I have an invoice table with: Invoice number, Part Number, Quantity, and Price.

I also have two tables with: Part Number, Part Name. There two tables are because they are two different categories of products.

I want to have a single column that will combine all of the part names that belong to an invoice number.

Example would be:

Invoice table:
[TABLE="width: 500"]
<tbody>[TR]
[TD]Invoice #[/TD]
[TD]Part Number[/TD]
[TD]Quantity[/TD]
[TD]Price[/TD]
[TD]Related 10000 Name[/TD]
[TD]Related 30000 Name[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]10125[/TD]
[TD]2[/TD]
[TD]100.00[/TD]
[TD]Apples[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]30524[/TD]
[TD]1[/TD]
[TD]50.00[/TD]
[TD][/TD]
[TD]Lettuce[/TD]
[/TR]
</tbody>[/TABLE]

I want to have a column that would say: "Apples Lettuce"
Even better, would be the column would say "Apples Apples Lettuce"

Is this possible in a calculated column or a measure?

If I combined the tables with product names so there is only one related column, would it make it easier to get to "Apples Apples Oranges"?

 

[one3nine0]

Oh, there will also be some products that do not have names in the related tables, as they will be excluded from the project I will be working on